[TASK] Simplify ci.yml workflow dispatcher

[ohader]

• omits having to use GH_TOKEN environment
• omits having to invoke the gh CLI

[ohader]

ℹ️ Please back-port to other relevant branches as well

[Copilot]

Pull request overview

This PR simplifies the nightly dispatcher workflows by switching from gh workflow run ... (and GH_TOKEN) to invoking the existing CI workflow as a reusable workflow.

Changes:

• Refactors nightly-main.yml and nightly-8.yml to call ./.github/workflows/ci.yml directly via uses:.
• Makes ci.yml reusable by adding workflow_call + an optional ref input.
• Updates the CI checkout step to use the provided ref input.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
.github/workflows/nightly-main.yml	Switches nightly main dispatch to a reusable workflow call.
.github/workflows/nightly-8.yml	Switches nightly 8 dispatch to a reusable workflow call with ref: '8'.
.github/workflows/ci.yml	Adds workflow_call support and uses a ref input for checkout.

Comments suppressed due to low confidence (1)

.github/workflows/nightly-main.yml:12

• nightly-main previously always ran CI against the main branch (explicit checkout + --ref main). Now the reusable workflow is invoked without ref, so a manual run from another branch would test that branch instead of main. If the intent is to always validate main, pass with: ref: 'main' (or hardcode the checkout ref in ci.yml when called from this workflow).

        name: "dispatch-nightly-main"
        uses: ./.github/workflows/ci.yml

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[Copilot]

inputs.ref is referenced unconditionally, but the inputs context is only populated for workflow_call / workflow_dispatch runs. Since this workflow still runs on push and pull_request, those events may fail at expression evaluation with an unrecognized context. Use github.event.inputs.ref (which safely resolves to empty when not present) or switch to a fallback like github.sha/github.ref without referencing inputs for non-call runs.

[Copilot]

Behavior change vs the previous gh workflow run ci.yml --ref 8: this now runs the current branch's ci.yml definition (via local uses: ./.github/workflows/ci.yml) while checking out code from ref: '8'. If branch 8 expects a different CI workflow version, this will no longer match; consider calling a workflow from 8 (e.g., using uses: owner/repo/.github/workflows/ci.yml@8) or explicitly confirming that CI should be driven from main for the 8 branch.

[ohader]

Good question. Why was the 8 branch test triggered from main before?